Submission #689966

#	Time	Username	Problem	Language	Result	Execution time	Memory
689966		NK_	Paths (BOI18_paths)	C++17	100 / 100	436 ms	66220 KiB

paths

// Success consists of going from failure to failure without loss of enthusiasm
#include <bits/stdc++.h>

using namespace std;

#define nl '\n'

using ll = long long;

int main() {
	cin.tie(0)->sync_with_stdio(0);
	
	int N, M, K; cin >> N >> M >> K;

	vector<int> A(N); for(auto& x : A) { cin >> x; --x; }

	vector<vector<int>> adj(N);

	for(int i = 0; i < M; i++) {
		int u, v; cin >> u >> v; --u, --v;
		// cout << u << " " << v << nl;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}

	vector<vector<ll>> dp(N, vector<ll>(1<<K));

	for(int i = 0; i < N; i++) dp[i][1<<A[i]] = 1;

	ll ans = 0;
	for(int s = 1; s < (1<<K); s++) {
		for(int u = 0; u < N; u++) if (dp[u][s] != 0) {
			// cout << "FIN: " << u << " " << s << " " << dp[u][s] << nl;
			if (__builtin_popcount(s) != 1) ans += dp[u][s];
			for(const auto &v : adj[u]) {
				if ((s >> A[v]) & 1) continue;
				dp[v][s^(1<<A[v])] += dp[u][s];
				// cout << "MOVE: " << v << " " << (s ^ (1<<A[v])) << " " << dp[v][s^(1<<A[v])] << nl;
			}
		}
	}
	cout << ans << nl;


    return 0;
}

• Subtask 1: 23 / 23
• Subtask 2: 20 / 20
• Subtask 3: 27 / 27
• Subtask 4: 30 / 30